Cycle burglar alarm

ABSTRACT

Unauthorized use or movement of a cycle is prevented by an electrical circuit including tilt and tamper switches connected with a wheel engaging retractable cable and alarm device controlled by a key operated switch.

United States Patent [191 Kennedy et al.

[ Aug. 28, 1973 CYCLE BURGLAR ALARM [22] Filed: May 4, 1972 [21] Appl.No.: 250,261

3,678,455 7/1972 Levey 340/63 Primary Examiner-Alvin H. WaringAttrneyRobert K. Rhea 7 ABSTRACT [52] US. Cl 340/65, 200/42, 180/114 [51Int. Cl. Br 25/10 Unauthorized use or movement of a cycle is prevented[58] Field of Search 340/52 H, 63, y an ri l cir i including ilt andtamper 200/42, 44; 180/1 14 switches connected with a wheel engagingretractable cable and alarm device controlled by a key operatedReferences Cited switch.

UNITED STATES PATENTS 3,673,562 6/1972 Buell 340/63 8 Claims, 4 DrawingFigures J 20 F M I CYCLE BURGLAR ALARM BACKGROUND OF THE INVENTION 1.Field of the invention The present invention relates to alarm systemsand more particularly to an alarm circuit preventing unauthorized use ormovement of a cycle.

2. Description of the prior art Unauthorized use alarm systems forvehicles, such as automobiles, is disclosed by US. Pat. Nos. 3,422,398and 3,453,591 which incorporate and functions with the vehiclecomponents to trigger an alarm in response to actions of an intruder butso far as we known the prior art does not disclose burglar alarm systemsfor cycles.

This invention is distinctive over these two patents by providing ahousing containing a battery operated circuit containing a retractablewheel engaging cable and i a tilt responsive switch with an alarm devicewhich is controlled by a key operated switch.

SUMMARY OF THE INVENTION A preferably metallic housing, containing acable connected with a retracting reel, battery and audible signalmeans, is mounted in an out-of-the-way place on the cycle. A keyoperated switch, secured to one wall of the housing, forms a part of aseries circuit interconnecting the battery with the signal means andretractable cable through a gate controlled silicon rectifier andincluding a mercury switch and a tamper switch in a manner that if thecable is cut or broken or if the cycle is moved the alarm will sound andcontinue until the circuit is opened by the key operated switch. Apush-button switch, connected with the circuit in parallel with the keyoperated switch, permits operation of the signal means in traffic.

The principal object of this invention is to provide an audible alarmsystem preventing unauthorized use or movement of a cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of abicyle illustrating the alarm system mounted thereon in operativeposition;

FIG. 2 is a perspective view, to a larger scale, of the alarm systemcontaining housing mounted on a fragment of a cycle frame andillustrating, by dotted lines, the position of a key in the key operatedswitch;

FIG. 3 is a back elevational view of the housing to another scale; and,

FIG. 4 is a schematic wiring diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENT Like characters of referencedesignate like parts in those figures of the drawings in which theyoccur.

In the drawings:

The reference numeral indicates a substantially conventional bicyclehaving a frame 12 and wheels 14 and 16.

The reference numeral 18 indicates the alarm system, as a whole,comprising a housing 20 containing an electric circuit 22. The housing20 is provided with a back wall 24 having a pair of clamps 26 securedthereto which connect the housing to a selected portion of the frame 12.One end portion of the housing is provided with louvered openings 27 forsound wave emission.

Obviously, the housing 20 may be mounted in any selected location on thecycle, such as under the seat, where suitable. The housing contains acoaxial or shielded cable 28 secured at one end to a conventionalcentrifugal locking ratchet reel 30 within the housing which releasesand rewinds the cable 28 by a spring, not shown, in response to manualcontrol of the free end of the cable. The cable 28 is extended or pulledout, at its free end, from the housing through an opening 32 formed inthe housing wall opposite its back surface 24. The purpose of the cable28 is to surround and attach the cycle to a fixed object, such as a postor rack, or be inserted through the spokes of one or more of the cyclewheels when the cycle is standing free. The housing 20 also contains anaudible signal device, such as a horn H, at least partially surroundedby a protective shield or grid 36. The reel, cable and horn form a partof the electrical circuit 22, as hereinafter explained.

A battery B, such as a six volt dry cell battery, contained by thehousing, has its negative terminal connected with the cathode 38 of asilicon gate controlled rectifier SR in series through a key operatedswitch KS by wires 35 and 37. The anode 40 of the rectifier SR isconnected with one terminal of the horn H. The other terminal of thehorn H is connected to the positive terminal ofthe battery 8 by a wire41 thus forming a first series circuit. A resistor 42 is connected tothe wire 37 and to the center or pole connected terminal of a singlepole two-position function switch FS. One terminal of the'functionswitch FS is connected by a wire 44 to the reel connected end of theinner or center conductor 46 of the shielded cable 28. The other freeend of the cable conductor 46 is provided with a plug 48 which enters ajack J, mounted on the housing back wall 24, in turn connected in serieswith the tamper switch TS and second resistor 50 to the positiveterminal wire 41. The first and second resistors 42 and 50, with thecomponents connected in series therewith to the battery B, form avoltage divider second series cir cuit for the purposes presentlyexplained.

A third circuit comprising a wire 52, connected at one end with the gateelectrode 54 of the rectifier SR, is connected at its other end to theterminal of the resistor 50 opposite the positive wire 41. Thegateelectrode 54 is also connected to the wire 35 in series through athird resistor 60 by a wire 56. The junction of the wire 52 and resistor50 is connected to the horn grid 36 by a wire 62.

The shield 64 of the cable 28 is connected to the pos itive wire 41 by awire 66. The positive wire 41 is grounded to the housing by a wire 68.The other terminal of the function switch FS is connected to the coaxialcable center conductor 46 through a series connected mercury switch MS.A push-button switch PS is connected with the wires 35 and 37 inparallel with the key switch KS and a fourth resistor is similarlyconnected across the terminals of the push-button switch in parallelwith the key switch KS. The push-button switch in addition to being usedfor sounding a warning in traffic also assures that the horn willfunction when the alarm system is turned on. A fifth resistor 72 isconnected with the horn terminals.

The resistor 50 has substantially more resistance than does the resistor42. Thus, with the key switch closed and the cable plug 48 engaged withthe jack 1, a negative voltage is applied to the gate electrode 54 ofthe rectifier SR which maintains the rectifier nonconductive from itsanode to cathode. As long as the key switch KS, function switch FS andtamper switch TS remain closed and the cable engaged with the jack J,negative bias voltage on the gate electrode 54 maintains the rectifierSR nonconductive and the horn inoperative. However, in the event anyportion of the second series circuit between the resistor 42 and theresistor 50 is interrupted, a positive voltage is applied to the gateelectrode 54 from the battery positive terminal reducing the internalresistance of the rectifier to render it conductive between its anodeand cathode permitting current thorugh the first series circuit thusoperating the horn H. The current will continue and the horn H willcontinue to function in sounding an alarm until the key operated switchKS is opened to interrupt the circuit.

To prevent theft of the cycle by its being bodily picked up and carriedaway, for example, the function switch FS may be closed with its otherterminal connected with the cable center conductor 46 through the seriesconnected mercury switch MS which acts as an anti-tilt switch which isopened by movement of the cycle. The mercury switch MS similarlycompletes the second series circuit from the resistor 42 to the resistor50 normally biasing negative voltage to the gate electrode 54 of therectifier SR in the manner just described.

The tamper switch TS is a microswitch which is closed by mounting thehousing on the cycle in such a manner that any attempt to remove thehousing opens the switch TS which sounds the alarm in the mannerdescribed.

A further safety feature or anti-theft arrangement is achieved by thenegative voltage biasing circuit being connected with the hornprotective grid 36 so that in the event an attempt is made to disarm orrender the horn H inoperative by an object inserted through one of thelouver openings 27, the negative voltage biasing series circuit will begrounded to the housing so that the positive current renders therectifier SR conductive to sound an alarm. Similarly, a furtherprotective feature resides in connecting the cable shield 64 to thebattery positive terminal wire 41 so that if the cable shield 64 iscontacted or an attempt made to cut it the alarm will sound.

The purpose of the resistor 60, preferably having a resistance equal tothe resistance of the resistor 50, is to in effect bias the key switchKS toward the negative during the current surge resulting from closingthe key switch KS.

The purpose of the resistor 70 is to reduce the current surge in thefirst series circuit as it is opened and closed by operating thepush-button switch PS and prevents firing or rendering the rectifier SRconductive when the alarm system is turned on" by closing the key switchKS.

The purpose of the resistor 72 is to supply a continuous current or loadto the rectifier SR by acting as a spark suppressor so that therectifier will maintain a conductive state, from anode to cathode,during such time as contact points of the horn H are open when the alarmsystem is sounding an alarm.

Obviously the invention is susceptible to changes or alterations withoutdefeating its practicability, therefore, we do not wish to be confinedto the preferred embodiment shown in the drawings and described herein.

We claim: 1. An alarm system for a cycle, comprising: a source of directcurrent; an electrically operable alarm device; a solid state gatecontrolled semiconductor triode rectifier having an anode, cathode andgating electrode; first circuit means connecting said current sourcewith said alarm device and said rectifier in a first series circuit foractivating said alarm device by current passing through said rectifierfrom the anode to the cathode, said rectifier having a high internalresistance so that it is normally in a nonconductive state until avoltage of predetermined magnitude and polarity is applied between saidgating electrode and said cathode to reduce the electrical resistance toa low value,

said low value of electrical resistance permitting current to passcontinuously through the rectifier between the anode and cathode untilthe current in said first series circuit is interrupted;

at least one normally closed switch means arranged to be opened by aperson unauthorized to contact said cycle;

first and second electrical resistance means;

a voltage divider circuit connecting said current source with saidnormally closed switch means in series between said first and secondelectrical resistance means forming a second series circuit; and,

a third circuit connecting said gating electrode with said second seriescircuit between said switch means and said second electrical resistancemeans for applying a voltage of predetermined magitude and polarity tosaid gating electrode and normally maintaining said rectifiernonconductive between its anode and cathode,

whereby when said normally closed switch means is opened said thirdcircuit applies a voltage of predetermined magnitude and oppositepolarity to said gating electrode to render said rectifier conductivebetween its anode and cathode.

2. The alarm system according to claim 1 and further including:

a key operated switch connected in series in said first series circuit.

3. The alarm system according to claim 2 in which said normally closedswitch means includes:

a jack; and,

a coaxial cable having an electrical conductive shield surrounding acenter conductor, said center conductor having a plug formed on one ofits ends and removably received by said jack.

4. The alarm system according to claim 3 in which said normally closedswitch means further includes:

a microswitch.

5. The alarm system according to claim 4 in which said normally closedswitch means further includes:

a mercury switch.

6. The alarm system according to claim 5 in which said electricalconductive shield is connected with said first series circuit.

7. The alarm system according to claim 6 and further including:

a housing adapted to be connected with said cycle and surrounding saidalarm system.

8. The alarm system according to claim 7 and further including:

a normally open push-button switch connected with said first seriescircuit in parallel with said key operated switch for operating saidalarm device independently of said second series circuit.

1. An alarm system for a cycle, comprising: a source of direct current;an electrically operable alarm device; a solid state gate controlledsemiconductor triode rectifier having an anode, cathode and gatingelectrode; first circuit means connecting said current source with saidalarm device and said rectifier in a first series circuit for activatingsaid alarm device by current passing through said rectifier from theanode to the cathode, said rectifier having a high internal resistanceso that it is normally in a nonconductive state until a voltage ofpredetermined magnitude and polarity is applied between said gatingelectrode and said cathode to reduce the electrical resistance to a lowvalue, said low value of electrical resistance permitting current topass continuously through the rectifier between the anode and cathodeuntil the current in said first series circuit is interrupted; at leastone normally closed switch means arranged to be opened by a personunauthorized to contact said cycle; first and second electricalresistance means; a voltage divider circuit connecting said currentsource with said normally closed switch means in series between saidfirst and second electrical resistance means forming a second seriescircuit; and, a third circuit connecting said gating electrode with saidsecond series circuit between said switch means and said secondelectricAl resistance means for applying a voltage of predeterminedmagitude and polarity to said gating electrode and normally maintainingsaid rectifier nonconductive between its anode and cathode, whereby whensaid normally closed switch means is opened said third circuit applies avoltage of predetermined magnitude and opposite polarity to said gatingelectrode to render said rectifier conductive between its anode andcathode.
 2. The alarm system according to claim 1 and further including:a key operated switch connected in series in said first series circuit.3. The alarm system according to claim 2 in which said normally closedswitch means includes: a jack; and, a coaxial cable having an electricalconductive shield surrounding a center conductor, said center conductorhaving a plug formed on one of its ends and removably received by saidjack.
 4. The alarm system according to claim 3 in which said normallyclosed switch means further includes: a microswitch.
 5. The alarm systemaccording to claim 4 in which said normally closed switch means furtherincludes: a mercury switch.
 6. The alarm system according to claim 5 inwhich said electrical conductive shield is connected with said firstseries circuit.
 7. The alarm system according to claim 6 and furtherincluding: a housing adapted to be connected with said cycle andsurrounding said alarm system.
 8. The alarm system according to claim 7and further including: a normally open push-button switch connected withsaid first series circuit in parallel with said key operated switch foroperating said alarm device independently of said second series circuit.